Auto-injection device

ABSTRACT

The present disclosure relates to an autoinjector device for use in combination with a syringe, said syringe comprising a movable plunger; a needle; and a tubular needle shield. The claimed autoinjector device comprises: an elongated housing having a proximal and a distal end; a drive mechanism; a syringe holder in order to support the fragile syringe and to prevent damage to the syringe. The invention furthermore relates to a method for assembly of the autoinjector device according to the invention.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 16/871,897, filed May 11, 2020, which is a continuation of U.S.patent application Ser. No. 16/045,820, filed Jul. 26, 2018, which is acontinuation of U.S. patent application Ser. No. 15/809,398 filed Nov.10, 2017, which is continuation of U.S. patent application Ser. No.15/065,670, filed Mar. 9, 2016, now U.S. Pat. No. 10,137,248, which iscontinuation of U.S. patent application Ser. No. 14/365,635, filed Jun.15, 2014, now U.S. Pat. No. 9,867,940, which is a U.S. National PhaseApplication pursuant to 35 U.S.C. § 371 of International Application No.PCT/SE2012/051365 filed Dec. 10, 2012, which claims priority to U.S.Provisional Patent Application No. 61/570,921 filed Dec. 15, 2011. Theentire disclosure contents of these applications are herewithincorporated by reference into the present application.

FIELD OF DISCLOSURE

The present invention relates to an auto injection device for use incombination with a syringe, and a method for assembling said syringe inthe autoinjector device.

BACKGROUND

Different types of autoinjectors are frequently used in order tofacilitate administration of drugs to patients. When the proximal end ofthe autoinjector is correctly positioned against the intended area ofthe skin of the patient, an activation means on the autoinjector ispressed in order to activate the autoinjector. When activated, a needlerapidly punctuates the skin and the drug is delivered via the needleautomatically.

There are two different categories of the autoinjectors on the markettoday. The first one uses custom designed medicament chambers, examplesof these are described in WO2003/099358 and WO01/93926, while the secondcategory uses standard pre-filled syringes. There are several advantagesdirected to the use of standard pre-filled syringes, for example thesyringes have already been tested and approved in accordance withpresent regulations, which saves time and reduces the overall costs forthe autoinjector. The present invention is directed to disposableautoinjectors used in combination with standard pre-filled syringes.

Since the autoinjectors are often used for self-administration of a drugto, the punctuation of the patients skin and the delivery of the drugvia the needle are preferably performed rapidly which requires that asignificant force is applied to the syringe by the drive mechanism.However, syringes are fragile and when the force of the drive mechanismis applied, there is a significant risk that the fragile syringe breaks.

In WO2007/083115 an autoinjector comprising a syringe support deviceintended to be arranged around the syringe and support the syringe atits front is disclosed. The support device reduces the risk of damage tothe syringe but there is till a significant risk that the fragilesyringe is damaged when a large force from the drive mechanism isapplied upon activation of the autoinjector.

There is consequently still a need for an improved autoinjector devicethat further reduces the risk of damage to the syringe.

SUMMARY

The present invention, defined in the appended claims, provides anautoinjector device that fulfils the needs defined above.

The autoinjector device of the present invention is elongated along alongitudinal axis A and has a proximal end and an opposing distal endand comprises

-   -   a syringe having a substantially circular cross section having        an outer diameter, said syringe having a proximal end comprising        a neck and a distal end provided with a from the outer periphery        of the container radially extending flange; said syringe further        comprising a movable plunger, a needle and a tubular needle        shield having a outer diameter which is larger than the outer        diameter of the syringe,    -   an elongated autoinjector housing comprising a space for said        syringe;    -   a driving mechanism arranged in the distal end of the housing in        order to, when the autoinjector is activated, apply a force on        the movable plunger;    -   a syringe holder having a syringe holder wall with a        substantially tubular shape, said holder wall having:    -   an open distal end provided with a distal supporting collar        arranged around the outer periphery of said syringe holder wall        to support said syringe by the radially extending flange,    -   an open proximal end provided with a proximal supporting collar        arranged around the inner periphery of said syringe holder wall        to support said syringe neck, and    -   a slot extending from said open proximal end in the distal        direction resulting in a C-shaped cross sectional shape of the        syringe holder wall in the proximal end.

According to one aspect of the invention, the holder wall has alongitudinal length between the proximal supporting collar and the adistal supporting collar corresponding to the length of the syringe suchthat the a distal supporting collar of said syringe holder wall supportssaid radially extending flange of said syringe and said proximalsupporting collar supports said neck of said syringe simultaneously whena force is applied on the movable plunger.

According to a further aspect of the invention, the proximal supportingcollar has a inner diameter which is lesser than the outer diameter ofthe syringe and

According to another aspect of the invention, the proximal supportingcollar has a inner diameter which is lesser than the outer diameter ofthe tubular needle covering shield.

According to a further aspect of the invention the proximal supportingcollar is capable of flexing radially outward for allowing the tubularneedle shield to pass through when the syringe is longitudinally mountedin relation to the longitudinal axis (A) within the syringe holder.

The claimed invention fulfils the needs defined above since the syringeholder according to the invention provides support for the syringe alongthe entire length of the syringe. Furthermore the distal end of thesyringe holder, due to the corresponding length of the syringe holder,will be in contact with the radially extending flange at the distal endof the syringe and support the flange when the force from the drivemechanism is applied. Since the syringe is supported both at theproximal end by the collar in contact with the neck and at the distalend by the flat surface in contact with the flange of the syringe, therisk that the syringe is damaged when a drive force is applied by thedrive mechanism is reduced considerably.

A further advantage with the claimed injector device is that theC-shaped proximal end of the syringe holder facilitates the fitting ofthe syringe in the holder since the C-shaped cross section makes itpossible for the proximal end of the syringe holder to flex and therebyallow the tubular needle shield, even though it has a diameter exceedingthe inner diameter of the collar, to be moved past the collar. Once thesyringe is fitted in the syringe holder the C-shaped collar will providethe desired support around almost the entire syringe neck which isfavourable since the load on the syringe neck will be distributed over alarger area and the risk of damage to the syringe is reducedconsiderably.

In one embodiment of the invention, the autoinjector device comprisesguiding means to control the movement of the syringe holder within theautoinjector housing when the syringe holder is longitudinally mountedin relation to the longitudinal axis (A) within the autoinjectorhousing. This is a favourable embodiment of the autoinjector devicesince the guiding means will assist during the preparation of theautoinjector device. The syringe is first fitted in the syringe holderby introduction of the proximal end of the syringe into the syringeholder via the distal end of the syringe holder and then moved in theproximal direction of the autoinjector device to the intended positionwithin the proximal housing section during assistance by the guidingmeans that facilitates the mounting of the syringe and the syringeholder in the housing.

In one embodiment of the invention, the guiding means comprisesprotrusions arranged along the outer periphery of the syringe holderwall and corresponding grooves arranged along the inner periphery of theautoinjector housing. This embodiment of the guiding means providessatisfying guiding during the preparation of the autoinjector device.

One embodiment of the invention comprises corresponding openings orwindows in the autoinjector housing and the syringe holder which make itpossible to easily verify that the syringe is correctly fitted inrelation to the syringe holder and the autoinjector housing.

In one embodiment of the invention, the syringe holder comprises lockingmeans that secures the syringe holder in relation to the autoinjectorhousing when the syringe holder is longitudinally mounted in relation tothe longitudinal axis (A) within the autoinjector housing.

In one embodiment of the invention, the outer periphery of the proximalend of the syringe holder is radially supported by a contact surface onthe inside surface of the autoinjector housing when the syringe holderis in a proximal position within the autoinjector housing. Thisembodiment is favourable since the contact surface of the autoinjectorhousing will prevent the proximal end of the syringe holder wall fromflexing radially outwards, which ensures that the syringe remains in theintended position in the syringe holder when the drive force is appliedby the drive mechanism.

The different embodiments described above could of course be combinedand modified in different ways without departing from the scope of theinvention that is defined by the claims. Further details of theinvention will be described in the detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

One embodiment of the present invention is illustrated in the appendedfigures, said figures disclosing:

FIG. 1 illustrates a perspective view of a syringe assembled in asyringe holder.

FIG. 2 illustrates a perspective view of a syringe holder.

FIGS. 3 a, 3 b and 3 c illustrate exploded views of the autoinjectordevice at different steps during the assembly of the autoinjectordevice.

DETAILED DESCRIPTION

In FIGS. 3 a to 3 c , selected components of an autoinjector device 10according to the invention are illustrated. The autoinjector device 10,elongated along a longitudinal axis A, is intended forself-administration of drugs and has a proximal end 11 and an opposingdistal end 12.

The autoinjector device comprises an autoinjector housing divided into aproximal housing section 13 and distal housing section 14 in order tomake the space defined inside the housing accessible for assembly of thedifferent components of the autoinjector.

The autoinjector housing has the shape of a tube. The autoinjectorhousing is intended to house a pre-filled syringe 30 within a syringeholder 40. A drive mechanism (not shown) is also arranged within thehousing. The drive mechanism is arranged to apply a proximally directeddrive force to a movable plunger in the syringe in order to expel thedrug through a needle (not shown).

The drive mechanism is not illustrated in detail in the drawings butdifferent types of drive mechanisms are available. The drive mechanismmay comprise a pre-tensioned spring which upon activation applies apre-determined pressure via plunger rod (not shown) to the movableplunger arranged in a distal end of the syringe.

The autoinjector is intended for use in combination with a standardpre-filled syringe 30. The syringe 30, assembled in the syringe holder40 illustrated in perspective in FIG. 2 , has a substantially circularcross section having an outer diameter. The syringe is normally made ofglass in order to ensure a reliable and hygienic storing of the drug inthe syringe 30. At a proximal end of the syringe 30, the outer diameteris reduced and shaped like a neck 32 at which a needle (not shown) andneedle shield 34 are attached before delivery of the syringe. In orderto ensure that the needle remains sterilized before use, the needle isprotected by the needle shield 34 having a substantially circular crosssection and having an outer diameter which is larger than the outerdiameter of the elongated syringe. The tubular needle shield 34 may be aso-called Rigid Needle Shield (RNS). Further, the tubular needle shield34 encloses the needle and is removably fastened to the syringe 30 atthe neck 32. The distal end of the tube-shaped syringe 30 is arrangedwith a radially extending flange 35. The syringe 30 furthermorecomprises a movable plunger arranged in the distal end of the syringe 30to seal the syringe 30 and ensure that the pre-filled drug of thesyringe remains in the syringe 30. The movable plunger is preferablymade of a rubber material in order to achieve a seal between the innerperiphery of the syringe 30 and the plunger.

The syringe 30 is secured in the autoinjector housing by a syringeholder 40 that is described in more detail below. The syringe holder 40is arranged in the proximal housing section in order to support andmaintain the syringe 30 in a pre-determined position in relation to thesyringe holder and the autoinjector housing. During assembly of theautoinjector, the syringe 30 is first inserted in the syringe holder 40,which is then moved in the proximal direction of the autoinjector device10 to a forward position where the syringe holder 40 is secured in theproximal housing section. The movement of the syringe holder in theproximal housing section is facilitated by guiding means 41 consistingof corresponding longitudinal protrutions 42 along the outer peripheryof the syringe holder 40 and longitudinal recesses along the innerperiphery of the proximal housing section. Furthermore correspondingsnap-fitting fastening means 43 are arranged on the syringe holder 40and the proximal housing section in order to permanently secure thesyringe holder in the desired proximal position within the proximalhousing section.

The syringe holder 40 provides a reliable and effective support for thefragile syringe 30 and reduces the risk of damage to the syringe 30. Oneembodiment of the syringe holder 40 is illustrated in FIG. 2 in aperspective view, where it is separated from the other components of theautoinjector device. The syringe holder 40 has a tubularly shaped holderwall 44 with a proximal end 45 and a distal end 46. The proximal end 45of the syringe holder is open but provided with a proximal supportingcollar 47 arranged around the inner periphery of said syringe holderwall in order to support said syringe neck 32 in the proximallongitudinal direction. Further, the proximal supporting collar 47 has ainner diameter which is lesser than the outer diameter of the elongatedsyringe and thus also lesser than the outer diameter of the tubularneedle shield. A slot 48 extends from said open proximal end in thedistal direction resulting in a C-shaped cross sectional shape of thesyringe holder wall in the proximal end. The C-shaped holder wall in theproximal end 45 is able to flex radially outward which is essential inorder to fit the syringe 30 in the syringe holder 40 since the tubularneedle shield 34 has an outer diameter exceeding the inner diameter ofthe opening in the proximal supporting collar 47. This means that thesyringe 30 may be fitted in the syringe holder 40 from the distal end 46of the syringe holder. The syringe 30 is then moved in the proximaldirection within the syringe holder 40. When the tubular needle coveringshield 34 reaches the proximal supporting collar 47, the C-shaped holderwall will flex radially outward and thereby make it possible to move thesyringe 30 further until the neck 32 of the syringe 30 is in contactwith the collar 47, i.e the desired position of the syringe 30 withinthe syringe holder 40. In this position the needle shield 34 hascompletely passed the supporting collar 47, allowing the C-shaped holderwall to flex back, radially inward, behind the needle shield, such thatthe collar supports the syringe at the neck 32.

The syringe holder 40 furthermore comprises a distal supporting collar49 arranged around the outer periphery of said syringe holder wall 44and has a longitudinal length between the proximal supporting collar 47and a distal supporting collar 49 that corresponds to the length of thesyringe 30 so that the distal supporting collar 49 of said syringeholder wall, when the syringe 30 is fitted in the desired positionwithin the syringe holder 40, is in contact with the proximal side ofthe radially extending flange 35 of the syringe 30 and provides furthersupport for the fragile syringe 30 within the syringe holder 40 at thesame time as the proximal supporting collar 47 supports the neck 32 ofsaid syringe 30. Thereby the risk of damage to the syringe 30 is reducedsignificantly. The syringe holder 40 furthermore comprises guiding meansthat facilitates its movement in the longitudinal direction of theautoinjector device and locking means for securing the syringe holder inthe proximal housing section before assembly of the syringe in thesyringe holder 40.

The proximal housing section is furthermore provided with a window 15,or opening, corresponding to the slot 48 in the syringe holder 40 whenthe syringe holder 40 is fitted in the intended position in the proximalhousing section in order to make the syringe 30, and the drug in thesyringe, visible from the outside of the autoinjector housing andpossible for the patient to verify that the autoinjector device iscorrectly assembled and ready for use.

Three different assembly steps of the autoinjector device areschematically illustrated in FIGS. 3 a-3 c . In FIG. 3 a , the proximalhousing section and the syringe holder 40 are illustrated without thesyringe 30 fitted in the syringe holder 40. The syringe holder 40 ismovably arranged in the proximal housing section between a distalposition and a proximal position. Prior to fitting the syringe in thesyringe holder the syringe holder is arranged in the distal positionready for assembly.

The assembly of the autoinjector device 10 is initiated by fitting thesyringe 30 in the syringe holder 40 by inserting the proximal end of thesyringe in the distal end of the syringe holder 40 and pushing thesyringe in the proximal direction until the neck 32 of the syringe 30 isin contact with the collar 47 in the proximal end of the syringe holder40, where the collar has a plurality of radially inward directedshoulders 47 a, illustrated in FIG. 3 b . The syringe 30 and the syringeholder 40 are then moved simultaneously in the proximal direction to theproximal position in the proximal housing section. In the proximalposition, the outer periphery of the proximal end of the syringe holder40 will be surrounded by support surfaces 16 on the inside surface ofthe proximal housing section. The cross sectional shape of the supportsurfaces correspond to the outer periphery of the syringe holder inorder to provided a rigid support and prevent the C-shaped wall of theproximal end from flexing radially outwards in order to secure thesyringe 30 in the syringe holder 40 and the autoinjector device 10,illustrated in FIG. 3 c . Finally, the autoinjector housing is closedaround the syringe 30 by fitting the distal housing section to theproximal housing section.

The assembly method of the present invention accordingly comprises thesteps:

-   -   a). Inserting the proximal end of the syringe 30 in the distal        end of the syringe holder 40;    -   b). Moving the syringe 30 towards the proximal end of the        syringe holder until the neck 32 of the syringe 30 is in contact        with the proximal supporting collar 47 and the radially        extending flange 35 of the syringe 30 in contact with the distal        supporting collar 49 of the syringe holder 40;    -   c). Moving the syringe holder 40 and the syringe 30        simultaneously towards the proximal end of the autoinjector        device 10.

The different embodiments described above could be combined in differentways and modified further without departing from the scope of theinvention that is defined by the claims.

The invention claimed is:
 1. A method of assembling a subassembly of amedical delivery device, the method comprising the steps of: providing ahousing having a longitudinal axis and a support surface located on aninside surface of the housing; partially inserting a syringe holder intothe distal end of the housing, where the syringe holder has an opendistal end and an open proximal end having radially inward directedshoulders arranged around an inner periphery of the open proximal end;providing a syringe having a needle shield affixed to the proximal endof the syringe adjacent to a neck portion of the syringe, where theneedle shield has an outer diameter; forming a first axial configurationof the subassembly by inserting the proximal end of a syringe into thedistal end of the syringe holder and moving the syringe axially relativeto the syringe holder so that the needle shield is pushed through theopen proximal end until the neck of the syringe is supported by theradially inward directed shoulders; forming a second axial configurationof the subassembly after forming the first axial configuration byaxially moving the syringe holder and the syringe proximally relative tothe housing until the support surface abuts an outside surface ofsyringe holder so as to prevent the radially inward directed shouldersfrom flexing radially outward.
 2. The method of claim 1 furthercomprising contacting a flange of the syringe with a distal supportingcollar of the syringe holder.
 3. The method of claim 1 furthercomprising moving both the syringe holder and the syringe simultaneouslyto form the second configuration of the subassembly.